...2.1 Phases of The Cell Cycle 2.1.1 Interphase Originally this phase of the cell cycle was called the "resting stage", since light microscopy could not detect any activities taking place within the cells. Today, however, it is known as a stage of considerable activity at the molecular and sub-cellular level and is usually subdivided into: * G1 - ("Gap One") - this is a period of molecular synthesis where a newly formed cell turns on a variety of genes on its DNA to make proteins, which in turn churn the metabolism of the cell, produce and breakdown carbohydrates, lipids, etc., and transform energy from food into ATP. The cell grows and enlarges. * S - ("synthesis") - during this phase the chromatin (DNA and proteins) becomes synthetically active. Using elaborate teams of enzymes, the DNA molecules of each chromosome are copied by semiconservative DNA synthesis. This phase cannot be clearly seen or distinguished under the light microscope, even with DNA stains, as the material is too diffuse. However, the making of new DNA molecules can be monitored by following the incorporation of radioactive isotopes into the newly forming DNA molecules. * G2 - ("Gap Two") - another period, of variable length, in which cells prepare for division. Many different proteins are synthesized, especially those that will act as spindle fibers (protein "ropes"). Stocks of energy are accumulated and many organelles, such as mitochondria, also grow and divide, increasing in number.• Interphase...
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...2.0 DISCUSSION 2.1 Phases And Events Of The Cell Cycle 2.1.1 Phases And Subphases Generally, there are two phases in cell cycle. Those are interphase and mitotic phase. Figure 1.0: The cell cycle Interphase consist of G1, S, and G2. The name of G actually represent as “gap” while S represent as “synthesis”. So, the name for G1 is also known as “first gap”, S is “synthesis”, and G2 is “second gap”. There is a reason why it is called “gap”. It is because, when the cells were observed long time ago, it appeared as inactive which in inactive period, it create a gap between S phase and mitotic phase. However, as the world hurtles down the path of fast scientific development, we now know that there is a growth and metabolic activity inside cells. The mitotic phase is divided into two, mitosis and cytokinesis. Mitosis consist of prophase, prometaphase, metaphase, telophase, and anaphase. 2.1.2 Duration Of Cell Cycle Approximately, G1 takes about 5 – 6 hours, S takes about 10 – 12 hours, and G2 takes about 4 – 6 hours. Mitotic phase takes less than 1 hour. Overall, a normal human cells take about 24 hours to complete a cell cycle. 2.1.3 Events In The Cell Cycle In each subphases, several events occurred in well ordered. Starting from G1, the growth of cells occurred in this phase by producing proteins and cytoplasmic organelles. Until at the end of G1, the enzymes required for DNA synthesis become more active. The process continue with S phase, in this entire phase,...
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...Cell Cycle A cell spends the most time in the stage of interphase. The first stage of interphase is known as G1 phase. G1 is where most of the cell growth occurs. After the G1 phase, the cell goes through the G1 checkpoint and if the cell is well developed, it will proceed to the S phase. During S phase, the DNA of the cell is synthesized, or copied. The cell then enters G2 phase in which the cell prepares for cell division. The cell goes through a G2 checkpoint. If the cell doesn’t have any problems in relation to the cell’s growth and development, then the cell is ready for mitosis. There are two parts to cell division, mitosis followed by cytokinesis. Mitosis is the process in which the nucleus of the cell splits into two. The four stages of mitosis are prophase, metaphase, anaphase, and telophase. During prophase, the cell’s nuclear envelope disappears and the chromatin tightly coils to become visible chromosomes. Each chromosome contains two sister chromosomes that are held together at the centromere. The cell then enters metaphase where the spindle fibers located at the centrioles attach to the centromeres. The sister chromatids are then pulled to the middle of the cell and lined up in the center. The third checkpoint occurs here to make sure that the chromosomes are aligned, if so then it proceeds to anaphase. During anaphase the centromeres split and the sister chromatids are pulled to opposite poles of the cell. The cell then enters telophase in which the chromosomes...
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...THE CELL CYCLE WORKSHEET Name: Catherine Dauw Date: 3 Novmeber 2015 Per: A A) The diagram below shows six cells in various phases of the cell cycle. Note the cells are not arranged in the order in which the cell cycle occurs. Use the diagram to answer questions 1-11. M Phase 1. Cells A & F show an early and a late stage of the same phase of the cell cycle. What phase is it? C 2. Which cell is in metaphase? A 3. Which cell is in the first phase of M phase (mitosis)? D (interphase), A (prophase), F (prophase), C (metaphase), E (anaphase), and B (telephase) 4. List the diagrams in order from first to last in the cell cycle. 5. In cell A, what structure is labeled X? spindle fibers 6. Are the cells depicted...
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...collectively known as the cell cycle. Interphase includes the three stages: G1, S, and G2. The G1 (growth) phase is where the cell prepares for DNA and chromosome replication, taking approximately 10 hours. The S phase, 9 hours long, is where the DNA and chromosomes actually replicate giving 2 exact copies called sister chromatids. In G2, the cell takes four hours to prepare for cell division. Mitosis itself takes only an hour and occurs in both haploid and diploid cells. The duplicated chromosomes separated into two nuclei. The five stages of mitosis are prophase, prometaphase, metaphase, anaphase and telophase. After mitosis is complete, cytokinesis...
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...THEY AFFECT ITS ROLE IN THE CELL CYCLE P53 plays a very important role in controlling the cell cycle. Defective p53 can cause multiplication of abnormal cells, which leads to cancer. Over 50% of human tumours contain p53 mutants. Damaged DNA and some stress signals can activate the increase of p53 proteins while normally; the p53 protein level is available in lower quantities. To reduce the damaged DNA, p53 can repair DNA; it can perform growth arrest and initiate apoptosis (cell death). Description of p53 p53, which is also known as TP53 or a tumour protein, has its locus on the chromosome 17p13.1 and codes for a protein. The p53 protein is responsible for tumour suppression: it stops the formation or growth of cancerous...
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...The Life Cycle Assessment of Cell Phones The mobile phone has become an essential product all around the world. A small handheld device with the ability call, send messages, and access the internet from almost anywhere in the world has become a necessity for many citizens of developed countries. Due to rapid technological advances, cellular phones become obsolete in a very short period of time. The average lifespan of a cell phone is only 18months in the US (LCA of Cell Phones). With over 233 million active cell phones in use in the US alone and 4 billion worldwide, it’s mindboggling to consider how many phones that have been created and discarded over the past few decades. 1. What environmental impacts are the most significant? The energy usage costs accounts for over 30% of the total life cycle energy (LCA of Cell Phones). Depending on how the electricity is created (coal, natural gas, oil, etc.) lots of greenhouse gases and other pollutants are released into the air. 2. What lifestage(s) contribute the most to these impacts? Energy usage occurs in the Product Consumption stage. The daily recharging of the battery is a huge energy obligation. 3. What are the strengths, flaws, and limitations of the analysis? The analysis has a great amount of cell phone data within the US and gives great examples of LCA goals from companies like AT&T and Nokia. However there is almost no information about the LCA from the global perspective. Also there is no information...
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...N Driving the Cell Cycle Through Metabolism Ling Cai and Benjamin P. Tu Annu. Rev. Cell Dev. Biol. 2012.28. Downloaded from www.annualreviews.org by Ecole Polytechnique Federal Lausanne on 06/20/12. For personal use only. Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038; email: benjamin.tu@utsouthwestern.edu Annu. Rev. Cell Dev. Biol. 2012. 28:3.1–3.29 The Annual Review of Cell and Developmental Biology is online at cellbio.annualreviews.org This article’s doi: 10.1146/annurev-cellbio-092910-154010 Copyright c 2012 by Annual Reviews. All rights reserved 1081-0706/12/1110-0001$20.00 Keywords cell growth, cell proliferation, metabolic cycle, growth control, nutrients, yeast Abstract For unicellular organisms, the decision to enter the cell cycle can be viewed most fundamentally as a metabolic problem. A cell must assess its nutritional and metabolic status to ensure it can synthesize sufficient biomass to produce a new daughter cell. The cell must then direct the appropriate metabolic outputs to ensure completion of the division process. Herein, we discuss the changes in metabolism that accompany entry to, and exit from, the cell cycle for the unicellular eukaryote Saccharomyces cerevisiae. Studies of budding yeast under continuous, slow-growth conditions have provided insights into the essence of these metabolic changes at unprecedented temporal resolution. Some of these mechanisms by which cell growth and proliferation...
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...Chapter 8 The Cellular Basis of Reproduction and Inheritance Multiple-Choice Questions 1) The creation of offspring carrying genetic information from a single parent is called A) asexual reproduction. B) sexual reproduction. C) a life cycle. D) regeneration. E) spontaneous generation. Answer: A 2) Which of the following statements regarding sexual and asexual reproduction is true? A) Cell division only occurs after sexual reproduction. B) Only offspring from asexual reproduction inherit traits from two parents. C) Sexual reproduction typically includes the development of unfertilized eggs. D) Sexual reproduction is more likely to increase genetic variation than is asexual reproduction. E) Only asexual reproduction results from the union of a sperm and an egg. Answer: D 3) Strictly speaking, the phrase "like begets like" refers to A) all forms of reproduction. B) sexual reproduction only. C) asexual reproduction only. D) production of gametes from a premeiotic cell. E) sexual reproduction between different species. Answer: C 4) Asexual reproduction requires ________ individual (s). A) 0 B) 1 C) 2 D) 3 E) 4 Answer B 5) With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because we have A) identical chromosomes, but different genes. B) identical genes but different chromosomes. C) the same combination of traits...
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...10th 2011 The Cell Cycle Directions: Answer the following questions. Cite references as needed. Be sure to read the required Module 3 readings and view the required Web sites before completing the assignment. Cell Cycle Questions for Cell Cycle 1) . Briefly describe all phases of the cell cycle and tell what happens in each. a) Interphase: G1 phase, S phase, G2 phase Interphase: Before a cell can enter cell division, it needs to take in nutrients. All of the preparations are done during the interphase. Interphase proceeds in three stages, G1 phase, S phase, G2 phase. Cell division operates in a cycle. Therefore, interphase is preceded by previous cycle mitosis and cytokinesis (Module 3 Readings). a. G1 phase: The cell increases the supply of proteins and increases its organelles. b. S phase: Linear chromosome is replicated. c. G2 phase: Increases protein preparing to replicate. (Module 3 Readings) b) M phase: M phase is a method of indirect cell division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species. 2) Which phase is the shortest? Anaphase is the shortest phase of mitosis because its where the chromatids twins are all pulled apart at the centromere by the spindle fibers. 3) What is G0 (Gap 0/Resting phase)? A resting phase is when or where the cell has left the cycle and has stopped dividing. 4) If a cell never entered the...
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...For L18: 8.19, 21.4, 11.1 , 6.13, 10.9, 11.3, 3.16 For L19: 11.3, 8.9, 8.1, 8.2, 4.3 For L20: 8.8, 8.3, 8.4, 8.7 For L22: 8.7, 8.8 and 11.17 For L23: 4.16, 8.8, 10.4, 11.10, 11.17, 11.18 For L24: 27.1, 27.2, 8.4, 8.5, 8.6, 8.12 For L25: 8.1, 8.11, 8.12, 8.13 For L26: 8.12, 8.13, 8.14, 8.15 and 27.3 For L27: 8.12, 8.13, 8.15 and 27.3 For L28: 27.3, 27.4, 27.5, 27.9, and 27.15 For L29: 27.7, 27.8, 27.15, 27.16 and 27.17 Exam 3 (11/9/15) Supplemental Reading: 26.4 (Hypothalamus and Pituitary glands) 27.6 (Menstrual cycle) For each question below you need to be able to write a paragraph answer that is clear, accurate and detailed and in many cases draw, label and explain an answer with detail, clarity and accuracy, or create a detailed accurate table. Have someone who will give you honest feedback read your paragraphs and listen to your explanations for clarity, especially those that you are having trouble with. Check your notes and book for accuracy, or have someone who knows confirm you are accurate. To confirm you have enough detail, make sure you use all of the terms that follow each question in your paragraph and in your drawing and explanation. If you are missing or incorrectly use one term in ten that is a grade of A-, two terms in ten is a B, three terms in ten is a C, and if you miss or incorrectly use more than four terms in ten you are headed for failing the exam and need to study more. Before the exam you need to be able to...
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...BY 101 Study Guide Chapter 9 – Cell Division Cell division is an elegant process that enables organisms to grow and reproduce. Through a sequence of steps, the replicated genetic material (chromosomes) in a parent cell is equally distributed to two daughter cells. While there are some subtle differences, mitosis is remarkably similar across organisms. Before a dividing cell enters mitosis, it undergoes a period of growth called interphase. Interphase is the "holding" stage or the stage between two successive cell divisions. In this stage, the cell replicates its genetic material and organelles in preparation for division. The cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to its division and duplication (replication). The cell cycle consists of four distinct phases: G1 phase, S phase (synthesis), G2 phase (collectively known as interphase) and M phase (mitosis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's chromosomes are divided between the two daughter cells, and cytokinesis, in which the cell's cytoplasm divides forming distinct cells. Activation of each phase is dependent on the proper progression and completion of the previous one. Cells that have temporarily or reversibly stopped dividing are said to have entered a state of quiescence called G0 phase. Mitosis is composed of several stages: * Prophase * Metaphase * Anaphase * Telophase Prophase ...
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...Multimodal Treatment for Cancer and It’s Nursing Implication Cure: Complete eradication of malignant cells Control: prolonged survival and containment of cancer cell growth Palliate: relief of symptoms associated with the disease Surgery 2. Chemotherapy 3. Radiation therapy Surgery A. Diagnostic Biopsy: to obtain a tissue sample for analysis of cells suspected to be malignant Actual tumor Lymph Nodes 3 Most Common types of Biopsy Excisional: most frequently used for easily accessible tumors of the skin, breast, upper and lower gastrointestinal tract, and upper respiratory tract. : removal of the entire tumor and the surrounding marginal tissues as well Incisional: when the tumor mass is to large to be removed. : a wedge of a tissue from the tumor is removed for analysis Needle Methods: performed to sample suspicious masses that are easily accessible, such as some growth in the breasts, thyroid, lung, liver and kidney : fast, relatively less expensive and easy to perform and usually require local anesthesia. B. Surgery as a Primary Treatment: Local Excisions (Debulking) Wide or Radical Excision (en block dissection) removal of the primary tumor, lymph nodes, adjacent involved structures, and surrounding tissues that may be at high risk for tumor spread C. Prophylactic Surgery: involves removing nonvital tissues or organs that are...
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...University of Phoenix Material Comparing Cell Cycles Complete the Cell Cycle charts below. Describe the events in each phase for Cell Cycle A. Compare the steps in mitosis and meiosis for Cell Cycle B. Cell Cycle A |Phase |Describe the events in each phase | |G1 (1st growth stage) |This is the portion of the cell cycle just after division, but before DNA synthesis. During this| | |time the cell grows by producing proteins and organelles. | |S (Synthesis) |DNA synthesis (or replication) occurs during this phase. At the beginning of the phase, each | | |chromosome is single. At the end, after DNA replication, each chromosome consists of two sister | | |chromatids | |G2 (2nd growth stage) |This third subphase of interphase is a period of metabolic activity and growth. During this | | |phase the cell makes final preparations for division. | |Prophase of mitosis |Prophase occupies over half of mitosis. The nuclear membrane breaks down to form a number...
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...visit the Writing Center in the Student Success Center. | Part 1: An organism is born, lives, and then dies. Similarly, a cell has a life cycle.After reading pages 164 – 165 in your textbook, outline the six stages of the cycle of a cell. | 10 points | Answer:1. Interphase- when the cell is going about regular activities 2. Prophase- when the DNA chromosomes first become visible 3. Metaphase- When the chromos line up in the middle 4. Anaphase- when the chromos form pairs and are apart 5. Cytokinesis- when the cell has two separate nuclei and is about to split into two different cells | Part 2: The portion of the life cycle that involves the separation of the nuclear (DNA) material of the cell is termed mitosis. Two cells that are formed from one during this type of division are identical to each other and to their parent cell. So as to understand this complicated process, scientists have identified and named specific events that occur. After reading pages 166 – 167 in your textbook, outline the six stages of mitosis. | 10 points | Answer: 1. Early Prophase 2. Prophase 3. Transition to Metaphase 4. Metaphase 5. Anaphase 6. Telophase | Type your name here: Chanulae M. Smith Type your name here: Chanulae M. Smith (See next page for part 3) Part 3: Mitotic cell division needs to be finely regulated. The cell cycle has checkpoints that...
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